Heart failure has reached epidemic proportions in the United States and is responsible for nearly 500,000 deaths each year. The majority of heart failure cases is now the result of infarction- induced left ventricular (LV) remodeling. The lack of a well-established effective treatment has lead to a continually expanding list of medical and surgical options for the palliation of heart failure patients. Coronary artery bypass grafting (CABG) and surgical ventricular restoration (SVR) are the two surgical options included in the ongoing $38 million NIH-sponsored multi- center randomized STICH trial (to be completed in 2008). Another recently completed randomized trial has shown for the first time a benefit of CABG + SVR over CABG alone in patients with heart failure caused by coronary artery disease. Moreover, it confirms that the SVR procedure can be performed safely in patients with severely reduced LV function. Broad, Long-Term Objective: Develop and validate a public-domain software tool that will enable clinicians to easily simulate the effects of CABG and SVR on patients with ischemic heart failure. Specific Aims: 1. Develop physics-based simulations of CABG and SVR using only public-domain software. 2. Perform pre- and post-operative CT and MRI exams on STICH patients in order to quantify their LV wall geometry and function and coronary artery anatomy and blood flow distribution. 3. Validate the simulations in Aim #1 using the LV function and coronary blood flow data acquired in Aim #2. In addition, as part of a repository for wide dissemination to the user community, CABG and SVR models will be made available via the simulation tool kit (SimTK) of Stanford's National Center for Physics-Based Simulation of Biological Structures (Simbios). These models and tools will complement work that is ongoing as part of one of the Simbios driving biological problems lead by Dr. Charley Taylor that focuses on blood flow and grafts in the aorta, and will provide a larger repertoire of fluid flow modeling capabilities in SimTK. The resulting computational models provide additional information not otherwise available. Specifically, cardiac surgeons will be able to predict the effects of CABG and SVR on individual patients before surgery. Most important, this bioengineering-based approach to further current understanding of myocardial structure-function relations in heart failure will offer clinicians an entirely new approach to assessment and treatment of their patients, which should ultimately lead to improved patient care.